Interchannel Interference Avoidance in MIMO Transmission by Exploiting Spatial Information

Abstract

Interchannel interference (ICI) is the key problem in wireless MIMO (multiple-input multiple-output) transmission. Numerous ICI reduction algorithms are reported in literature. It is common to these ICI reduction algorithms that they require considerable signal processing power. In this paper, a new approach is presented which avoids ICI and, thus, results in low complexity receivers whilst maintaining high spectral efficiency. It is demonstrated that this can be achieved for BPSK (binary phase shift keying) and QPSK (quadrature phase shift keying) modulation by compressing the symbols prior to transmission and by exploiting spatial information at the receiver. The V-BLAST (Vertical Bell Labs Layered Space-Time) algorithm and simple, low complexity MMSE (minimum mean squared error) and zero-forcing (ZF) detection without ICI reduction was used for comparison. It is shown that the new MIMO approach outperforms V-BLAST by about 6.5 dB at a signal-to-noise-ratio (SNR) of 15 dB while it outperforms direct MMSE detection by about 12 dB. In addition, it was found that the spectral efficiency compared to SISO (single-input single-output) is improved by a factor of 4 at about the same bit-error performance